Hello,This is my first post so I will try to keep it short and what I know to be true. (1) My maternal GF was born in Pola,Istria in 1905 as Rudolfo Mattuchina. The search for that record is under way. (2) In 1906 Ellis Island records show my GGM ( Catherina Mattuchina) ,arriving with her two children Rudolfo and Maria(my great aunt). The number 11-14083 was written over his occupation block , I understand this to be immigration verification. (3) My GF cetificate of naturalization states his name as Rudolph Matekine. Former nationality as Italy. And that he was naturalized in Chicago in 1943 however the certificate was'nt issued until 1967. (4) Death cerificate states name as Rudolph Matekine.
Question is: How do I prove the last name change from Mattuchina to Matekine? Would immigration records not hold this info? And how do I proceed? I welcome all responses. Charles

Matekine is the Anglicized version of the surname Mattuchina. The Italian version of Rudolph is Rudolfo, so he apparently obtained some American document based on his verbal statement of his name which was then written as it sounded.
I would think some kind of sworn statement that Rudolph Matekine is the same person as Rudolfo Mattuchina would suffice but I am no expert.

hi my name is andrew Matekine my fathers name is andrew matekine he had a brother with the name of rudy who was living in centerville iowa.rudy had a mother who remarried with a last name of kolak.I would love to talk more.